Method and apparatus for separating



March 3, 1964 G. w. WALKER 3,123,551

METHOD AND APPARATUS FOR SEPARATING ORE PARTICLES Filed Oct. 17, 1960 mfss 25 i l== i Ir a United States Patent Filed Oct. 17, 1960, Ser. No. 63,167 8 Claims. (Cl. 209-29) This invention relates to a new and improved centrifugal ore separator and method for separating ore particles.

The principal object of my invention is to provide an ore separator using in combination the rotation of a screen over which the ore is passed in crushed condition for screening purposes, air duct means below the screen to blow out upwardly the fine dust particles into an exhaust hood above for their removal by suction, while the other particles of rock are more or less floated on the screen and allowed to discharge therefrom peripherally partially by centrifugal action and partially by gravitation, while the heavier particles of metal drop down through the screen and are collected and removed by means of suitable screws to a suitable receptacle, thereby obtaining with a dry method and with simple mechanism in a most efficient manner as good or better results than were obtainable heretofore only by wet methods.

The ore separator of my invention is easily adjusted to $11? the different requirements presented by different ores.

(1) The pressure and volume of air is variable to suit different requirements;

(2) The speed of the screen disk may be varied and also the inclination thereof to suit different requirements;

(3) The rotary screen disk may be varied in diameter to suit different requirements, and

(4) The fineness of the screen may be varied to suit different requirements.

The invention is illustrated in the accompanying drawing, in which- FIG. 1 is a central vertical section through an ore separator made in accordance with my invention;

FIG. 2 is a fragmentary plan view taken on the line 22 of FIG. 1;

FIG. 3 is a sectional detail on the line 33 of FIG. 2, and

FIG. 4 is a fragmentary sectional detail corresponding to a portion of FIG. 1, showing a modified or alternative construction.

Similar reference numerals are applied to corresponding parts in these four views.

Referring first to FIGS. 1 to 3, the reference numeral 5 designates a variable speed electric motor, the armature shaft 6 of which carries a worm 7 transmitting drive to a worm gear 8 to drive a central vertical shaft 9 continuously in a clockwise direction, as viewed from above, and accordingly turn a generally conical screen 10 with respect to the open tops of a plurality of funnels 11 arranged in a circle under the screen with their upper ends covering substantially the complete bottom area thereof. The funnels 11 have discharge tubes 12 extending from the bottom thereof to conduct screened ore particles indicated at 13 to a suitable receptacle or conveyor, it being anticipated that this portion of the screened ore heavy enough to drop through the screen 10 but not heavy enough to drop into the air duct funnels 14 against upwardly discharging air 15 is worth retrieving and subjecting to further crushing torelease the metal particles which would doubtlessly be caught in the funnels 14 on the next pass through the machine. The metal particles are indicated at 16. Air under pressure is delivered to the lower portion of the funnels 14 through conduits 17, and metal particles 16 collected in the bottoms of the Ice funnels 14 are conveyed away to suitable receptacles or conveyors by power-operated screws 18.

The crushed ore indicated at 19 is delivered to the ore separator into a hopper 20 which has a discharge downspout 21 extending downwardly therefrom terminating in a flared lower end 22 in a predetermined elevated concentric relationship to a conical cap 23 secured to the upper end of the shaft 9 in elevated relationship to the annular drive flange 24 to which the inner ends of the triangular sections 25 of the screen 10 are secured, as indicated at 26. The crushed ore 19 flows by gravity under a predetermined head depending upon the length of the dovm-spout 21 and elevation of the hopper 20, and is fairly uniformly distributed on the screen 10 around the cap 23, and from this point on the crushed ore flows outwardly partly by gravity due to the inclination of screen 10 and partly by centrifugal force due to the rotation of screen 10, and, of course, in its outward travel the ore is gradually spread out more and more, as indicated by the curved dot and dash line 27 on both sides of FIG. 1. In this spreading out of the crushed ore fine dust particles, indicated at 28, will immediately be blown upwardly by the air 15 and collected in a conical hood 29 disposed over the ore separator in concentric relationship to the screen 10 and be carried away through dust exhaust conduits 30 by suction fans, as indicated by the arrows 31. The metal particles 16 being heavier will drop through the screen 10 into funnels 14, and there is ample opportunity for these metal particles to be separated in this way because, as shown in FIG. 1, the funnels 14 cover the major portion of the area of the underside of the screen 10. Any larger crushed ore particles too light to drop through the screen 10 against the upward flow of air, even though small enough to pass through the screen, will have an opportunity to drop through, as indicated at 13, into funnels 11 for further processing to retrieve the mineral particles therein, but the remaining crushed ore particles, indicated at 32, leaving the marginal edge portion of the screen 10 are lighter than the particles 13 and contain little or no ore particles or are too large to pass through the screen 10, and will be discharged onto an annular ledge 33 that slopes downwardly for discharge of these crushed ore particles into an annular gutter 34 in which a suitable number of paddles 35, turning with the screen 10, are arranged to operate to discharge the crushed ore through openings 36 at one point onto a suitable conveyor 37 to carry this crushed ore away to a refuse heap to be hauled away, unless tests reveal any likelihood of this ore being worth further crushing for reprocessing in the manner described, similarly as in the case of the particles 13, previously mentioned.

Rollers 38 are mounted on the outer ends of L-shaped arms 39 secured to the outer ends of segments 25 of the screen 10 to support the screen 10 at a predetermined elevation at circumferentially spaced points around the periphery thereof by rolling contact of rollers 38 in an annular track 40 which in turn is adjustable in elevation with respect to the base 41, the track 40 having a plurality of circumferentially spaced jack screws 42 extending downwardly therefrom freely through holes 43 in posts 44 and having nuts 45 threaded thereon and engaging the tops of the posts 44 and arranged to be adjusted by hand to increase or decrease the slope of the screen 10. The annular ledge 33, previously mentioned, is mounted on and adjusts up and down with the annular track 40. The paddles 35, previously mentioned, are hingedly connected as at 46 with the peripheral edge portion of the screen 10 so that a slight change in elevation of the screen will not affect the operation of these paddles in the annular gutter 34. The sections 25 of the screen 10 are flexibly connected by tapered gusset strips of neoprene or other suitable material, indicated at 47, whereby to compensate for the change in width of the 3 gaps between the sections as the screen is adjusted upwardly or downwardly at the periphery.

In the other figure, P16. 4, the funnel 11a corresponds to funnel 11, and there are three inner funnels 14a, 14b and 140 shown inside the funnel 1101, each with its own separate power-operated screw 18 in the bottom thereof to carry away the metal particles collected in these funnels, and each having its own separate air delivery tubes, as indicated at 17a, 17b and 17c, respectively, so that the air pressure and amount of air discharge is greatest at 1511, not as high at b, and least at 15c, whereby to have the most effective air blast through the thickest layer of crushed ore immediately around the cap 23 at the center of the screen 10, less air at an intermediate thickness about half way out from the center and still less air farther out. That should insure more eflicient removal of the fine dust and dirt particles 28 and more efficient sifting out from the crushed ore of the heavier metal particles 16, regardless of the difference in the thickness of the crushed ore on the screen 10 at the different levels. In other words, the air pressure and volume at 15b can be approximately equal to that at 15 in FIG. 1, but by increasing the pressure and volume at 15a, the efiiciency of the machine should be greatly increased, and likewise by decreasing the volume and pressure at 150 relative to that at 15b.

In operation, therefore, it should be clear from the foregoing description that in the present centrifugal ore separator I am enabled to accomplish with a dry method what it was possible to accomplish heretofore only with a wet method, the air blast or blasts serving to float the ore in its crushed condition as it is sifted, so that the heavier metal particles can be separated out and the lighter rock particles are discharged peripherally of the screen as it turns, using gravity to some extent and centrifugal force to some extent.

It is believed the foregoing description conveys a good understanding of the objects and advantages of my invention. The appended claims have been drawn to cover all legitimate modifications and adaptations.

I claim:

1. The method of ore separation which consists in continuously delivering in a vertical substantially cylindrical stream finely crushed ore containing free metal particles centrally on top of an upright generally conical screen that is of large diameter in relation to the cylindrical stream, turning the screen on a vertical axis at a speed bearing such relation to the rate of delivery of the crushed ore that this material flowing outwardly and downwardly partly by gravity and partly by centrifugal force is spread out in a fairly uniform thin layer of gradually diminishing depth toward the rim of said screen, the holes in the screen being large enough to allow dropping therethrough of metal particles in the ore, continuously delivering air under pressure upwardly through the holes in the screen to blow upwardly the smaller ore particles as dust while floating the larger ore particles relative to the screen on the air streams to prevent their dropping through the holes while allowing the metal particles by virtue of their greater weight to drop through said holes, collecting the metal particles that drop through the screen, conducting away the smaller ore particles that are blown upwardly as dust from the screen, and separately collecting the larger ore particles which after being floated outwardly over the screen drop by gravity from the rim thereof.

2 The method of ore separation as set forth in claim 1 including adjusting the upright generally conical screen to increase or decrease the angularity of the screen with respect to the axis of rotation to suit different ores being processed.

3. The method of ore separation as set forth in claim 1 including adjusting the upright generally conical screen to increase or decrease the angularity of the screen with respect to the axis of rotation to suit different ores being d processed, the method further involving increasing or decreasing the speed of rotation of the screen to suit different ores being processed.

4. The method of ore separation as set forth in claim 1 including adjusting the upright generally conical screen to increase or decrease the angularity of the screen with respect to the axis of rotation to suit different ore being processed, the method further involving increasing or decreasing the speed of rotation of the screen to suit different ores being processed, and further involving increasing or decreasing the delivery of air under pressure delivered through the openings in the screen to suit different ores or finenesses of ores being processed.

5. The method of ore separation as set forth in claim 1 including increasing or decreasing the speed of rotation of the screen to suit different ores being processed.

6. The method of ore separation as set forth in claim 1 including increasing or decreasing the speed of rotation of the screen to suit different ores being processed, and the method further including increasing or decreasing the delivery of air under pressure delivered through the openings in the screen to suit different ores or finenesses of ores being processed.

7. An ore separator comprising in combination an up right generally conical screen of appreciable diameter mounted for rotation on a central vertical axis, means connected with the rim portion of said conical screen for increasing or decreasing the angle thereof with respect to its vertical axis, an upright substantially cylindrical downspout of small diameter in relation to said screen disposed over the center of said screen and adapted to deliver a substantially cylindrical stream of finely crushed ore containing free metal particles centrally on top of said screen at a predetermined rate, drive means for turning said screen at a speed bearing a predetermined relation to the rate of delivery of the crushed ore so that this material flows outwardly and downwardly partly by gravity and partly by centrifugal force and is spread out uniformly thin and to gradually diminishing depth toward the rim of said screen, said screen having holes therein large enough to allow dropping therethrough of metal particles in the ore, means for continuously delivering air under pressure upwardly through the holes in the screen so as to blow upwardly the smaller ore particles as dust while floating the larger ore particles relative to the screen on the air streams to prevent their dropping through the holes while allowing the metal particles by virtue of their greater weight to drop through said holes, means under the screen for collecting the metal particles that drop through the screen, other means over the screen for conducting away the smaller ore particles that are blown upwardly as dust from the screen, and means extending annularly with respect to the rim of said screen for collecting the larger ore particles which after floating outwardly over the screen drop by gravity from the rim thereof.

8. An ore separator comprising in combination an upright generally conical screen of appreciable diameter mounted for rotation on a central vertical axis, said conical screen being composed of a plurality of generally triangular sections interconnected by flexible gussets, means connected with the rim portion of said conical screen for adjusting the inclination of said screen sections relative to the vertical axis of rotation of said screen, an upright substantially cylindrical downspout of small diameter in relation to said screen disposed over the center of said screen and adapted to deliver a substantially cylindrical stream of finely crushed ore containing free metal particles centrally on top of said screen at a predetermined rate, drive means for turning said. screen at a speed hearing a predetermined relation to the rate of delivery of the crushed ore, so that this. material flows outwardly and downwardly partly by gravity and partly by centrifugal force and is spread out uniformly thin and to gradually diminishing depth toward the rim of said screen, said screen having holes therein large enough to allow dropping therethrough of metal particles in the ore, means for continuously delivering air under pressure upwardly through the holes in the screen so as to blow upwardly the smaller ore particles as dust while floating the larger ore particles relative to the screen on the air streams to prevent their dropping through the holes while allowing the metal particles by virtue of their greater weight to drop through said holes, means under the screen for collecting the metal particles that drop through the screen, other means over the screen for conducting away the smaller ore particles that are blown upwardly as dust from the screen, and means extending annularly with respect to the rim of said screen for collecting the larger ore particles which after floating outwardly over the screen drop by gravity from the rim thereof.

References Cited in the file of this patent UNITED STATES PATENTS Russel Sept. 4, 1883 Stickney et al. Nov. 28, 1893 Stanley June 20, 1911 Stanley Aug. 10, 1915 Lightfoot July 18, 1933 Nolte Mar. 30, 1937 Smith Sept. 6, 1938 McLean July 6, 1943 Gannon et al. Apr. 5, 1949 Bowen Feb. 22, 1955 Hefi t May 14, 1957 FOREIGN PATENTS France Aug. 10, 1936 

7. AN ORE SEPARATOR COMPRISING IN COMBINATION AN UPRIGHT GENERALLY CONICAL SCREEN OF APPRECIABLE DIAMETER MOUNTED FOR ROTATION ON A CENTRAL VERTICAL AXIS, MEANS CONNECTED WITH THE RIM PORTION OF SAID CONICAL SCREEN FOR INCREASING OR DECREASING THE ANGLE THEREOF WITH RESPECT TO ITS VERTICAL AXIS, AN UPRIGHT SUBSTANTIALLY CYLINDRICAL DOWNSPOUT OF SMALL DIAMETER IN RELATION TO SAID SCREEN DISPOSED OVER THE CENTER OF SAID SCREEN AND ADAPTED TO DELIVER A SUBSTANTIALLY CYLINDRICAL STREAM OF FINELY CRUSHED ORE CONTAINING FREE METAL PARTICLES CENTRALLY ON TOP OF SAID SCREEN AT A PREDETERMINED RATE, DRIVE MEANS FOR TURNING SAID SCREEN AT A SPEED BEARING A PREDETERMINED RELATION TO THE RATE OF DELIVERY OF THE CRUSHED ORE SO THAT THIS MATERIAL FLOWS OUTWARDLY AND DOWNWARDLY PARTLY BY GRAVITY AND PARTLY BY CENTRIFUGAL FORCE AND IS SPREAD OUT UNIFORMLY THIN AND TO GRADUALLY DIMINISHING DEPTH TOWARD THE RIM OF SAID SCREEN, SAID SCREEN HAVING HOLES THEREIN LARGE ENOUGH TO ALLOW DROPPING THERETHROUGH OF METAL PARTICLES IN THE ORE, MEANS FOR CONTINUOUSLY DELIVERING AIR UNDER PRESSURE UPWARDLY THROUGH THE HOLES IN THE SCREEN SO AS TO BLOW UPWARDLY THE SMALLER ORE PARTICLES AS DUST WHILE FLOATING THE LARGER ORE PARTICLES RELATIVE TO THE SCREEN ON THE AIR STREAMS TO PREVENT THEIR DROPPING THROUGH THE HOLES WHILE ALLOWING THE METAL PARTICLES BY VIRTUE OF THEIR GREATER WEIGHT TO DROP THROUGH SAID HOLES, MEANS UNDER THE SCREEN FOR COLLECTING THE METAL PARTICLES THAT DROP THROUGH THE SCREEN, OTHER MEANS OVE THE SCREEN FOR CONDUCTING AWAY THE SMALLER ORE PARTICLES THAT ARE BLOWN UPWARDLY AS DUST FROMTHE SCREEN, AND MEANS EXTENDING ANNULARLY WITH RESPECT TO THE RIM OF SAID SCREEN FOR COLLECTING THE LARGER ORE PARTICLES WHICH AFTER FLOATING OUTWARDLY OVER THE SCREEN DROP BY GRAVITY FROM THE RIM THEREOF. 